Normally, when you surf the Web using Internet Explorer (or any other browser), websites that you visited are added to your browser "history". This allows you to navigate back quickly to sites that you have visited in the past -- for example, simply by typing "www" in the address bar of your browser, you'll see a drop-down list of some sites that you have visited recently:

Of course, this means that the next user of the computer could see your browser history as well (unless they log off and sign in under a different username). For privacy reasons, you may not want other users to see what sites you've visited recently.

Beginning in Internet Explorer 8, Microsoft added a new feature to Internet Explorer called "InPrivate Browsing", which allows the user to surf the Web without IE adding any of your visited sites to your browser history. To see what version of Internet Explorer you're using, hit the F1 button on your keyboard while IE is running, and the Help window will open up, displaying the version number at the top:

To turn on InPrivate Browsing, click the "Safety" button at the top of the Internet Explorer, and click the "InPrivate Browsing" option:

and a new window opens saying that you are now in InPrivate Browsing:

Note, however, that you now have two Internet Explorer windows open -- the new InPrivate Browsing window, plus the IE window that was previously open that you used to launch the new InPrivate Browsing window -- and InPrivate Browsing does not apply to the old window. Websites that you enter into that window will still be added to your browser history. (You can, of course, close that old browser window, so the only browser window you have open is the InPrivate Browsing one.)

Somewhat confusingly, you also cannot "turn off" InPrivate Browsing by clicking a button or selecting a menu option. Once an InPrivate Browsing window is open, you simply turn off InPrivate Browsing by closing that window.

NOTE: InPrivate Browsing will only provide a casual level of privacy protection, against the user who might sit down at the computer and glance at your browser history to see what websites you've been visiting. A truly nosy adversary might install spy software on your PC to track what websites you visit, and even to record what passwords you type in. (Such programs are commercially available, and while their manufacturers position them as "parental monitoring" programs in order to stay politically correct, they can of course be used by any user of a shared computer, to spy on any other user.) InPrivate Browsing will not protect against that type of spying software.

Bennett Haselton is a technology and political blogger who really comes out of his shell if you ask him how to bypass the Barracuda Web filter.